The reduced cigarette sidestream smoke papers or wrappers, as described in U.S. Pat. No. 4,231,377 Cline et al.; U.S. Pat. No. 4,420,002 Cline; U.S. Pat. No. 4,433,697 Cline et al.; U.S. Pat. No. 4,450,847 Owens; and U.S. Pat. No. 4,881,557 Martin use high levels of basic fillers (MgO/Mg(OH).sub.2 and CaCO.sub.3) to achieve reductions in the sidestream smoke of cigarettes. The filler concentrations in these papers are typically in the range of 14 to 60 grams per square meter, which is significantly higher than the 6 to 9 grams per square meter in regular cigarette paper. The high basis weights of these reduced cigarette sidestream smoke papers (typically 35 to 75 g/m.sup.2) and the resultant thickness increase, along with the "heat sink" effect caused by the thermal breakdown of magnesium hydroxide (shown in equation 1 below), causes an increased condensation of the smoke on the inside surface of the paper and within the paper structure itself. This smoke normally would penetrate through regular cigarette paper and form the typical sidestream smoke plume observed with regular cigarettes. ##STR1##
Extensive subjective taste studies have shown the taste characteristics of cigarettes wrapped in reduced cigarette sidestream smoke papers to have objectionable taste characteristics relative to regular cigarettes. Additional studies have also shown the pH of the mainstream smoke of tobacco columns wrapped in reduced sidestream smoke cigarette paper is higher than that of the same tobacco columns wrapped in regular cigarette paper. The subjective taste characteristics of cigarettes wrapped in reduced sidestream smoke cigarette paper are similar to that obtained when the pH of mainstream smoke of regular cigarettes is artificially increased.
The increased tar condensation on the inside surface of the cigarette paper and in the internal structure of the cigarette paper itself, along with the significantly higher level of basic fillers [MgO, Mg(OH).sub.2, and CaCO.sub.3) in the reduced cigarette sidestream smoke papers, results in a greater reaction of acidic smoke components with the basic fillers in the reduced sidestream smoke papers versus regular cigarette papers. This reaction results in nonvolatile tar components being formed which are not revolatilized back into the mainstream smoke but are pyrolyzed to lower molecular weight smoke components.